Rosemont is a neighborhood and census-designated place in Pennsylvania, on the Philadelphia Main Line. Partly in Lower Merion Township in Montgomery County and partly in Radnor Township in Delaware County, it is best known as the home of Rosemont College. It is the location of the 1894 gothic-revival Anglo-Catholic Church of the G…Rosemont is a neighborhood and census-designated place in Pennsylvania, on the Philadelphia Main Line. Partly in Lower Merion Township in Montgomery County and partly in Radnor Township in Delaware County, it is best known as the home of Rosemont College. It is the location of the 1894 gothic-revival Anglo-Catholic Church of the Good Shepherd.